Method ApiPlatform\Core\Bridge\Doctrine\Orm\Extension\FilterEagerLoadingExtension::getQueryBuilderWithNewAliases uses simple str_replace($aliases, $replacements, (string) $wherePart). So if i have embedded object in my entity being serialized it`s alias could be replaced.
For exampe: entity have embedded object in property "seo" and field expression would be "o.seo.slug". Using standard alias "o" the code produces "o_a2.seo_a2.slug" expression.